Plug supporting member for spark plug cleaners



March 23, 1943. H. RABEZZANA 2,314,556

' PLUG SUPPORTING MEMBER FOR SPARK PLUG CLEANERS Filed May 11, 1942 3nnento1:

Patented Mar. 23, 1943 PLUG SUPPORTING MEMBER FOR SPARK I PLUG CLEANERS Hector Rabezzana, Flint, Mich, assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application May 11, 1942, Serial No. 442,466

3 Claims.

My invention relates to spark plug cleaning devices of the type wherein a dry abrasive material is entrained by a stream of air under pressure and projected against the exposed inner end. of a spark plug to be cleaned whereby oil, soot, encrusted carbon and like deleterious materials which accumulate upon the electrodes when the plug is in use, and which deposits are likely to interfere with the proper operation thereof, are removed from said inner end and from the electrodes between which the sparks pass, and the plug restored to substantially its initial condition and made available for further use, the same as a new plug. My invention is designed for use, particularly, with spark plug cleaning devices such as are disclosed in my application for patent for a Spark plug cleaner, filed September 4, 1941, Serial Number 409,475.

The object of my invention is to provide an improved device for supporting a spark plug while the electrodes thereof (which are exposed to burning gases when the plug is in'use) are being cleaned by a jet of air and entrained abrasive material, as aforesaid; such supporting device being so designed and arranged as to prevent the abrasive material from injuring the external thread of the plug, which provides for the screwing thereof into an internally threaded hole in the wall of an internal combustion engine cylinder. That is the action of the jet of abrasive material is confined to the grounded shell electrode of the plug, and to the inner end of the entral electrode thereof; and is excluded from the externally threaded shell of the plug so that said thread is protected from injury by the abrasive material.

The preferred form of my invention is illustrated in the drawing accompanying and forming a part of this application although it may be embodied in other forms, so long as such other forms come within the scope of the concluding claims wherein the features wherein my invention consists are particularly pointed out.

In the drawing:

Figure 1 is a view showing a section of my invention taken upon a vertical central plane; a spark plug being shown as supported thereby and various jet and cleaner features being shown, so that the device may be clearly understood.

Figure 2 is a view showing my improved plug supporting member in plan.

Figure 3 is a view showing my improved plug support as seen from a position below the same, looking up.

Figure 4 is a fragmentary view illustrating a feature of my invention; this view being upon a larger scale than Figure 1 and a plug supported by the device being indicated by dotted lines.

Referring now to the drawing, the numeral 5 designates an angularly adjustable spark plug supporting member made, preferably, of vulcanj ized rubber, and having a passage extending axially therethrough and adapted to receive a plug to be cleaned, as illustrated in Figure 1; the lower end of said member having a depending annu lar portion 6 which extends into a sleeve 1 which is rotatable within a neck 8 fastened to them)- per end wall 9 of a cleaner casing, all as in my application for patent hereinbefore referred to. The supporting member has a series of peripheral notches l0 into which a spring-pressed detent ll may enter to thereby hold said member 5 and the sleeve 1 with which it turns in definite angular positions while the plug is being cleaned, the same as in my application above noted.

The axially arranged spark plug receiving passage in the member 5 comprises a lower portion I2 of such diameter as to receive the externally threaded lower end A of the shell of a spark plug (which screws into an internally threaded passage in a cylinder head or cylinder wall) and, preferably, with a larger upper portion 13 of such diameter as to receive the larger upper hexagonal portion B of said shell. Preferably the internal diameter of this larger part of the plug receiving passage aforesaid is less than the maximum dimension of the hexagonal portion of the shell of the plug to be cleaned; so that when the plug is pushed into the passage in the member 5 provided for its reception, see Figures 1 and 4, the upper end of the neck M of the member 5 into which the upper end of the plug receiving passage extends, will yield as the plug is placed within the passage; and will squeeze the angles of the hex as shown in Figure 1, and hold the plug in place within the passage provided for its reception while the plug is being cleaned.

Carried by the supporting member 5 so as to constitute a unitary part thereof, and so located that the lower end of the threaded portion A of the plug to be cleaned may abut against it when the plug is in place within the passage aforesaid, is an annular member l5 made of a hard material which will be resistant to the abrasive action of the material used to clean the plug. Porcelain or like ceramic material, a suitable metal, or other material having the requisite hardness may be used for this member; although I recommend that it be made of a ceramic material, such as unglazed porcelain.

The purpose of this member I5 is to prevent the abrasive material discharged by the nozzle C and used for cleaning the plug, from injuring the external thread upon the lower end A of the plug; this result being due to the fact that the abrasive material is prevented from impinging directly against 'the'lower end of the thread by the inwardly extending ledge provided by said member, and by the fact that said member l5 provides a bafile which restrains the entrance of abrasive material into the space between the threadedpart A of the plug and the passage [2 into which it extends.

Having thus described and explained'my invention I claim and desire to secure'by Letters Patent:

1. In a device of the class described. an angularly adjustable spark plug supporting member having an axial passage adapted to receive the threaded lower end of a spark plug to be cleaned; an annular member made of a material harder than said supporting member, located adjacent the lower end of said'passage, and which annular member extends inward beyondthe periphery of said passage so as to be engaged'by the lower end of aspark plug within said passage; and means for discharging a stream of air and' abrasive material against the lower end of a'spark plug supported within said passage; and located above said annular member. v

2; In a device of theclass described, an angularly adjustable spark plug supporting member having an axial passage adapted to receive the threaded lower end of a spark plug, and the upper end of which passage is enlarged so as to receive the enlarged upper end of a spark plug to be cleaned; an annular member made of a material harder than said supporting member located adjacent the lower end of said passage, and which annular member extends inward beyond the periphery of said passage so as to be engaged by the lower end of a spark plug within said passage; and means for discharging a stream of air and abrasive material against the lower end of a spark plug supported within said passage, and located above said annular member.

3, In a device of the class described, an angularly adjustable spark plug supporting member having an axial passage adapted to receive the threaded lower end of a spark plug to be cleaned; an annular member made of ceramic material disposed within and located above the lower end of said supporting member, and which annular member extends inward beyond'the periphery of said passage so as to be engaged by the lower end of a spark plug within said passage; means for discharging a stream of air and abrasive material against the lower end of a spark plug supported within said passage, and located above said annular member.

HECTOR RABEZZANA. 

